It is for a long time that equipments for the anaerobic fermentation of organic materials essentially comprise a fermenter in which the organic materials are caused to stay for some time with a view in particular to produce biogas.
The fermenter however, especially when it exhibits a substantial volume, raises problems of flow of the materials it contains.
In fermenters with a large volume indeed many rheologic phenomena occur in the vicinity of the introduction of the material as well as in respect of their transiting in the fermenters.
During the time of residence of the material within the fermenter, it is very difficult, even with the assistance of a vertical injection through the body of material within the fermenter, of biogas recycled and intended to displace this body of material from the inlet towards the outlet of the fermenter, to retain a homogenous viscosity within the whole bulk of this body of material.
In the peripheral zones inside of the fermenter there in particular remain amounts of material difficult to be kept under control.
Within these areas owing to the immovability of the material the viscosity would evolve with respect to the remainder of the medium, shearings would occur in the layers and it results therefrom a segregation of the different components. The heaviest particles would travel towards the bottom of the fermenter and create a deposit.
Such a sedimentation, if nothing is done, would be irreversible and evolving. The deposits would be increasing and continuously reduce the active volume of the fermenter and therefore its efficiency.
Since a fermenter is put in operation for many years, it is of prime importance to control this phenomenon, i.e. in short to solve the problem of the flow of the materials within the fermenters especially when the latter exhibits a large volume.
The present invention reaches this goal.